Three former youth-team footballers at Chelsea have launched legal claims against the club after allegations that black players were subjected to horrific racism by their coaches, including physical attacks and one instance when Graham Rix allegedly threw a cup of hot coffee in the face of one of the young prospects.

Rix, then the youth-team coach, is named along with Gwyn Williams, a prominent figure at Stamford Bridge for more than 25 years, in a case that contains such serious allegations Chelsea felt compelled to notify the Football Association and the police were brought in. The police decided after a seven-month investigation there was insufficient evidence to take any action but Chelsea have launched their own inquiry and the FA’s safeguarding team have so far interviewed two of the players. Chelsea have also offered in-house counselling to at least one of the players.

Rix and Williams declined to comment to the Guardian but later issued a statement through their solicitor denying the allegations. Chelsea have released a statement about a civil claim that was instigated in a letter to the club last February and, until now, has never been reported. “We take allegations of this nature extremely seriously,” Chelsea’s statement said. “We are absolutely determined to do the right thing, to fully support those affected, assist the authorities and support their investigations.”

Rix and Williams were key members of the backroom staff at a time when Glenn Hoddle, Ruud Gullit and Gianluca Vialli put in place a pre-Abramovich transformation to re-establish Chelsea as one of the more glamorous clubs in the country during the 1990s. Behind the scenes, however, evidence submitted to the FA and seen by the Guardian describes it as a “feral environment” for some of the black players in the youth team, one allegation being that they were treated “like a race of fucking dogs”.

I was a minor, I’d never heard those words being said to someone. He addressed me like that every time he saw me

In one incident, Chelsea played a youth-team fixture in Spain and Rix is said to have humiliated one of the black outfield players by substituting him with the reserve goalkeeper. As the player was showering afterwards, it is alleged Rix shouted that “if his heart was as big as his cock, he would be a great player that ran more”. According to the evidence seen by Chelsea and the FA, Rix followed it up by saying the player should have been “the only person in the whole stadium to be able to enjoy the 40-degree heat” on the basis that “blacks were always winning the long-distance Olympic events in the heat, if they weren’t chucking spears”.

Other allegations include that Rix or Williams called him a “darkie”, a “nignog”, a “black bastard”, a “wog”, “midnight”, “jigaboo” and various other insults. The player also alleges he was told by Williams to “fuck off back to Africa” and “sell drugs or rob old grannies”. Williams is not accused of any physical assaults but would allegedly punish the player by telling him to “go and clean my office, Richard Pryor – shine my shoes like a good wog” or “pick up your lip, it’s dragging on the floor”.

When the player left Chelsea for another team his new manager has said he wondered why a talented young footballer from one of England’s top clubs appeared to have been “stripped of his self-confidence”. That manager has submitted a written report that now forms part of the legal claim and says the player was “a good professional who always had a beaming smile but I always felt behind that smile was a person who clearly had his confidence knocked out of him at Chelsea. Whoever was responsible for that, I don’t know. He never gave me a problem. He was always on time and always gave his all.”

Now in his late-30s, the player is hoping others will come forward, describing himself as having “the weight of the world on my shoulders at 16” and saying the distressing effects have continued to affect him in his adult life. Every day, he says, he would walk to Chelsea’s training ground “thinking: ‘Oh my God, I can’t wait for this day to be over’ … I was so low. Even dragging this up now, it really affects me”.

Williams, 68, joined Chelsea in 1979 and was so close to Ken Bates he later followed him to Leeds United as technical director. His period at Chelsea also included a spell as assistant manager to Claudio Ranieri and he was involved in the scouting department for José Mourinho before leaving the club in 2006. Williams, who is credited with discovering John Terry, has been accused in the past of making homophobic comments to Graeme Le Saux, the former Chelsea defender. “He would wander up to me before training and say: ‘Come on, poof, get your boots on,’” Le Saux wrote in his 2007 autobiography. Williams was dismissed by Leeds for gross misconduct in 2013 after emailing pornographic images of women to a number of colleagues, including a female receptionist.

Rix, 60, also has a chequered past after admitting, in March 1999, two charges of unlawful sex with a 15-year-old girl and indecent assault and being sentenced to 12 months in prison – serving six of them – as well as being put on the sex offenders’ register for 10 years. He was reinstated by Chelsea immediately after his release from Wandsworth prison and was the first-team coach when Vialli’s team won the FA Cup in 2000. Rix had previously been the assistant manager to Gullit and had a brief spell as the caretaker manager after Vialli’s departure. After that, he managed Portsmouth, Oxford United and Hearts, as well as coaching at the Glenn Hoddle Academy in Spain and having a brief spell as manager of a club in Trinidad. His last managerial job in England was at AFC Portchester of the Wessex League Premier Division but he left the club last August.

Rix and his solicitor have not replied to a question from this newspaper about whether the FA temporarily suspended him after the allegations surfaced. The FA, asked the same question, has refused to comment and Paul Kelly, Portchester’s chairman, was due to speak to the Guardian before changing his mind after consulting the governing body. He had previously said the club was aware of the allegations and had followed all the procedures and guidelines set out by the FA.

The allegations from the player are also that Williams seemed to target him by “flicking my scrotum, flicking my penis, patting my bum” when he was still a minor. There is no suggestion Williams was getting sexual gratification but it was deemed serious enough to form part of the questioning when David Gregson, the FA’s safeguarding team leader, and Stefania Sacco, the safeguarding investigation manager, interviewed the player at Wembley on 23 October. Williams has been informed by the Guardian of the allegation.

The player says he tried to ring Graham Kelly, the chief executive of the FA, years later to talk to him about what had allegedly happened but says he was not even put through. “The FA have failed me in the way of not protecting me as a minor,” he says. “I was failed in terms of there not being enough parameters for protection.”

Williams with Ruud Gullit, the then Chelsea manager, in 1997. ‘Ruud Gullit didn’t even know what was going on,’ one player said in an interview with the FA. Photograph: Popperfoto/Getty Images

According to that player’s account, seen by the Guardian, the racist abuse at Chelsea started after joining the club on schoolboy terms. “Even at 12, 13, the vernacular he [Williams] was using was: ‘You little black bastard, you coon, you little wog, how are you doing?’ I was a minor, I’d never heard those words being said to someone [in football]. He addressed me like that every time he saw me. He’d walk in [the dressing room] and go: ‘Hey, look at the fucking blackies here then. Fucking rubber lips. Look at their fucking big noses. You black bastard. Been fucking robbing cars, have you?’ Let me tell you something – that is the most demoralising feeling you could ever have.”

In his interview with the FA’s safeguarding officials, the player adds: “I knew it was unacceptable but I was a minor. When you’re in that position, where this guy is a powerful guy at the club … I didn’t know how to handle it. I thought it would stop. I just didn’t know how to handle it and it was constant … the racial slurs of ‘coon’, ‘wog’, ‘monkey’ … ‘smoking wacky-backy’, which is marijuana, or ‘black bastard’, ‘fucking black bastard’, ‘mango-muncher’, ‘nigger’.

“Gwyn Williams has been at the club since 1979. He was powerful. He was Ken Bates’s mate. The guy [Williams] is a walking piece of dirt but he had power. It was said he had the biggest black book in London – he knew everyone. That guy was the governor. No matter what role he had, that man had power.”

When the player, then 15, was offered YTS terms Rix was the youth-team manager, with Williams in the role of youth development officer. Hoddle, who had been the manager, left Chelsea to take the England job and Gullit took over at Stamford Bridge. “The amount of times I wanted to say something to Ruud Gullit,” the player says in his FA interview. “But Ruud Gullit didn’t even know what was going on. They didn’t do these things in front of Ruud.”

It burned my face. I went to grab him. I wanted to kill this guy … I had to hold myself in

The player goes on to state in the same interview that when he asked Rix to stop “digging me out” he was struck on the back of the head and, later in a training session, kicked twice while sitting on the floor. Rix, he says, was singing the Billy Ocean song When the Going Gets Tough as the alleged assault took place.

In another training game, Rix joined in and, according to the player, hurled the ball into his face from a throw-in, leaving him on the floor with a bleeding nose.

The same player is said to have decided to stand up to Rix when, according to the evidence, the coach asked him whether he had “tried to fuck any of our white girls” at the weekend. In the ensuing argument, Rix allegedly threw a cup of coffee in his face. “It burned my face,” the player says. “I went to grab him. I wanted to kill this guy. Then I had to think … black boy, six foot whatever, hits a white coach – he’s out of football. So I had to hold myself in and I went in to put water on my face because it was burning.”

In a follow-up legal letter to Chelsea, another alleged incident refers to the teenager asking Rix to stop making his sister feel uncomfortable by making what were, in the player’s view, suggestive remarks. Rix allegedly went red with anger and replied: “I will do whatever I want and if I fancy a bit of black I guarantee her black arse will get it,” and then punched him in the scrotum. “Our client fell to the floor in excruciating pain and Rix walked off laughing while looking over his shoulder.”

Rix and Williams repeatedly told the Guardian through their solicitor, Eddie Johns, that they did not want to comment but Johns said in a statement after the story was published that his clients “deny all and any allegations of racial or other abuse”. He said Rix and Williams had cooperated with the police investigation and were cooperating with the FA. Johns added that the allegations had not been made directly to his clients but that they would deal with them if they were.